ORISKANY-WHITESTOWN SANDPLAIN. 197 
mile wide. Its height is uniform with that of the rest of the delta, from 
which it has been cut off by a postglacial ravine. Like many of the drift 
banks of the valley, it has suffered erosion on its riverward side. 
Oriskany-Whitestown sandplain.—This is a noteworthy accumulation 
stretching between the towns named on the southwest border of the val- 
ley. Its originand relations are not clear. The main mass or “ Oriskany 
bluffs” has an altitude of 540 feet. At Whitestown the altitude is 500 
feet. On the valley side the slope is chiefly a product of erosion ; on the 
west and southwest is a kame area, whose surfaces in part fall below and 
in part rise above the terrace, ranging between 480 and 600 feet. ‘The 
mags lies at the mouth of the Oriskany creek, but both the surface ex- 
pression and the internal structure appear to forbid the supposition that 
it is a delta related to that stream. Toward Oriskany an extensive open- 
ing at the base of the bluffs gives a section of 30 feet. At the bottom are 
15 feet of very coarse, much indurated gravel, with a profusion of cob- 
blestones and small boulders. Above the gravel a fine, sandy silt is 
exposed to a thickness of 15 feet. This silt is seen in fresh excavations 
along the way to Utica continuously for nearly a mile. About midway 
of the mass is a nearly complete section from the base to the top. At 
the base is an exposure of 30 feet of fine sand alternating with beds of 
very fine silt, which holds moisture and “ cuts like cheese.” Except at 
the top there is absolute freedom from gravelly material or even coarse 
sand. The beds incline slightly, but uniformly away from the valley. 
Above an unseen interval of 20 feet or more is a 45-foot section, showing 
15 feet of tumultuous coarse and bouldery gravel at the top, and below 
alternating sand and gravel with some cross-bedding. Its general incli- 
nation, however, as well as that of the silts below, is from 1 to 3 degrees 
southwest. A generalized section for the whole deposit, therefore, gives 
us a great body of fine silts intercalated between two massive bodies of 
glacial gravels. At Whitestown the coarse gravels are absent so far as 
seen. There is a slightly pebbly layer at the top, underlain by nearly - 
70 feet of very fine sand. Alternating thin layers are seen of finer or at 
least more coherent material, and with such regularity as to suggest a 
seasonal variation in deposition. The slopes here show evidence of ice 
contact and the water currents seem to have come from the north side 
of the beds. This fact and the inclination of the beds in the Oriskany 
bluff suggest a connection with the Nine Mile Creek delta, whose precise 
nature is, however, in doubt. The Oriskany beds are 20 feet higher than 
the edge of’the delta. But for this fact it would be reasonable to sup- 
pose that the delta deposits extended across the valley and have been 
breached by the river. Perhaps the two masses mark different stages of 
recession. 
